POWER SUPPLY APPARATUS

• US 20120248876A1
• Filed: 10/20/2010
• Published: 10/04/2012
• Est. Priority Date: 10/23/2009
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Inventors: Tamura, Hideki
• Granted Patent: US 9,086,463 B2
• Time in Patent Office: Days
• US Class Current: 307/66
• CPC Class Codes: G01R 31/386 using test-loads
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health

Abstract

A power supply apparatus includes a secondary battery and a timer unit for measuring a time required to charge the secondary battery from a first State Of Charge (SOC) to a second SOC, or a time required to discharge the second battery from the second SOC to the first SOC. The power supply apparatus further includes a determination unit for determining a degraded state of the secondary battery based on results of the measurement by the timer unit.

Claims

1. A power supply apparatus comprising:

a secondary battery;

a timer unit for measuring a time required to charge the secondary battery from a first State Of Charge (SOC) to a second SOC, or a time required to discharge the second battery from the second SOC to the first SOC; and

a determination unit for determining a degraded state of the secondary battery based on results of the measurement by the timer unit.

2. The power supply apparatus of claim 1, further comprising:

a charging unit for charging the secondary battery;

a discharging unit for discharging the secondary battery; and

a charging/discharging control unit for controlling charging of the secondary battery by using the charging unit and discharging of the secondary battery by using the discharging unit,

wherein the charging/discharging control unit controls the charging unit so that, at a predetermined timing, the secondary battery is charged from the first SOC to the second SOC, or controls the discharging unit so that, at the predetermined timing, the secondary battery is discharged from the second SOC to the first SOC.

3. The power supply apparatus of claim 2, wherein the determination unit stores, as an initial time required, the time required to charge the initial secondary battery from the first SOC to the second SOC, or the time required to discharge the initial secondary battery from the second SOC to the first SOC, and then determines the degraded state of the secondary battery by comparing the results of the measurement by the timer unit with the initial time required.

4. The power supply apparatus of claim 2, wherein the determination unit stores a capacity of the secondary battery, obtained when the initial secondary battery is in the second SOC, as an initial capacity, derives the capacity of the secondary battery in the second SOC based on the results of the measurement by the timer unit, and determines the degraded state of the secondary battery by comparing the derived capacity of the secondary battery with the initial capacity.

5. The power supply apparatus of claim 2, wherein the secondary battery is charged to a predetermined capacity or more and is then used as a backup power source for supplying power to a load appliance in case of emergency, and

wherein the charging/discharging control unit charges the secondary battery to a backup guarantee SOC or more, and varies the backup guarantee SOC so that the capacity of the secondary battery becomes the predetermined capacity or more depending on the degraded state of the secondary battery determined by the determination unit.

6. The power supply apparatus of claim 2, wherein the charging/discharging control unit controls charging/discharging so that an upper limit of the SOC of the secondary battery is less than 100%, and charges the secondary battery from the first SOC of less than 100% to the second SOC of 100% or discharges the secondary battery from the second SOC of 100% to the first SOC of less than 100%, at the predetermined timing.

7. The power supply apparatus of claim 2, wherein the secondary battery is charged to a predetermined capacity or more and is used as a backup power source for supplying power to a load appliance in case of emergency, and

wherein the charging/discharging control unit charges the secondary battery to a backup guarantee SOC or more, and varies the backup guarantee SOC so that the capacity of the secondary battery becomes the predetermined capacity or more depending on a temperature of the secondary battery.

8. The power supply apparatus of claim 5, wherein the charging/discharging control unit varies the backup guarantee SOC so that the capacity of the secondary battery becomes the predetermined capacity or more depending on a temperature of the secondary battery.